One of the oldest problems confronting the manufacturing industry has been how to develop methods of joining generally incompatible disparate materials into composite structures.
While methods have been developed for joining various disparate material together, the resultant bonds have generally proved less than desirable for a number of reasons.
While compatible material can be joined together in a strong, aesthetically pleasing manner, the materials that are considered incompatible produce entirely different results.
When a bond is formed between materials that are considered incompatible, the bond is usually bulky, structurally weak, and aesthetically unappealing. One of the main reasons for these results is the fact that an intermediate material, that is compatible to both of the incompatible materials must normally be used to create the structural connection between the elements.
To that end, super adhesives have been developed that join together many materials heretofore considered incompatible. Unfortunately these super adhesives are very difficult to work with, and control in a manufacturing process; and have therefore not met with widespread acceptance or use.
In addition many other methods have been developed that, while they are capable of joining the disparate material together, produce an unsightly seam interface, that must be cosmetically improved or obscured for aesthetic reasons.
Some examples of the prior art solutions to the aforementioned problems may be seen by reference to U.S. Pat. Nos. 3,962,015; 3,821,052; 2,650,185; 4,366,656 and 3,850,725.
The specific materials, that the present invention is concerned with, are metal and fiberglass; wherein the term "fiberglass" for the remainder of the specification is understood to mean a mixture of glass fibers and a hardenable liquid resin. These materials both enjoy widespread use in the manufacturing industry; however, due to the problems enumerated supra, they are normally not combined together as an integral external component of finished products.
In virtually every known instance that metal and fiberglass are joined together on an exterior surface, the connection is accomplished by purely mechanical means. In those other instances where the metal/fiberglass interface is not visible, either mechanical or chemical (specifically super adhesives) connections are employed.
Despite the failures of the aforementioned prior art methods, the present invention has been found to produce a structurally sound, virtually waterproof bond between metal and fiberglass, that also provides an aesthetically pleasing external interface between these materials.
By using the method taught by this invention, composite structures of metal and fiberglass can now be manufactured for exterior surface components used in the appliance, construction, and automotive industry or the like.